while it would seem to be "common sense" I don't believe there are any direct studies of the link between fiber activation and hypertrophy, other factors may (and probably are) be involved that mitigate the importance of this to some degree.

Also, if you are trying to develop strength, isolation exercises typically have no carryover to sports performance.

While that might be true, you can use compound movements that will stimulate move muscles at once.. what I would like to see on this is the degree at which one exercise stimulates secondary muscle groups... like squats on all the muscle groups in the lower leg.. that I think would be very useful information also

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Also, if you are trying to develop strength, isolation exercises typically have no carryover to sports performance.

I know some PLers who love things like push downs, and skull crushers for carryover into bench, and things like GMs and ab work for deads and squat. i consider those isolation. But ultimatley, althogh I do like to lift heavy weights now and again, PLing isn't my "goal"

Oh, and those studies that link "activation" to "hypertrophy" that you're looking for are probably classified under weight training just messin' w/ ya